EP1632308B1 - Linear guide with two parallel guide rails and method for producing it - Google Patents

Abstract

The system has two guide rails (10, 12) and two carriages (30, 32) with a spacing plate (20) welded, glued or otherwise fixed between them, so that the reference marks of the guide rails can also form the reference for the entire system. Other spacing plates (60) can also be welded, glued etc. between the carriages.

Description

The invention relates to a linear motion guide with at least two guide rails and in each case at least one carriage which is supported on the guide rails and can be moved along a longitudinal movement axis of the guide. Furthermore, the invention relates to a method for producing a linear motion guide (see, for example, US Pat. DE-19961869-A ).

In a widespread linear motion guide, a carriage is supported on at least one circulating unit arranged rolling or rolling elements on the guide rail. The carriage is moved along a longitudinal movement axis due to rotation of the rolling elements in the circulation unit on the rail. However, the invention covers not only such linear roller bearing guides but also, for example, those in which the carriage via sliding, fluid or magnetic bearing supported on the rail.

Linear motion guides are mainly used for translational, in particular rectilinear, movement and guidance of machine parts, as required for example in the movement of the translational axes of a machine tool. Although the linear guides are often used in a heavily polluted environment and in adverse conditions such as high temperatures, they require high precision. A prerequisite for ensuring a high precision of the movement of the machine parts is to ensure a great stiffness of leadership. The leadership should therefore not relocate or deform due to stress as possible. Likewise, the natural frequency of the machine part, which results from a carrier and the attached linear motion guide, should be as high as possible in a harmless region with a small vibration amplitude. Another essential prerequisite for a precise movement of the machine parts is that the rolling elements of the carriage do not pollute, since this has an adverse effect on the wear and the guiding accuracy.

The guide rails are for the most secure and rigid attachment to a support usually provided with orthogonal to their surface extending through holes, which are provided for receiving fasteners, such as screws.

In a specific application of such linear motion guides two rails are provided side by side, which have a fixed distance from each other and are then placed on the two carriages to form a linear motion system. After EP-A-1 060 829 For example, it is proposed to provide abutment edges on the guide rails, to fasten the guide rails adjusted to plates, etc., to place the carriages on the guide rails and to use certain surfaces of the guide rails and the carriages as adjustment surfaces of the overall system. Such a design according to the prior art is shown in Figures 1 and 2, in which the guide rails 101 and 102 are screwed onto a lower plate 104. The upper plate 106 is then screwed onto the carriages 110 and 112. A linear motor 114 serves to drive the linear motion system. According to the prior art cited here, it is quite possible to use abutment surfaces of the guide rails as Einjustierflächen in this embodiment and not, for example, the lower plate 104th

However, it has been found that this arrangement requires a high production cost and thus creates manufacturing redundancy. The original abutment surfaces are namely attached to the guide rails, but the bearing surfaces on the sub-assembly, so that a quasi-two-step reference is necessary here.

The invention is therefore an object of the invention to provide a generic linear motion guide and to propose a method for its production, so that the production cost is reduced without reducing the requirements for the adjustability of the overall system.

This object is achieved in a linear motion guide of the type mentioned by the measures of claim 1. The measures of the invention initially have the consequence that stop surfaces on the two guide rails continue to represent the Justierflächen for the entire system. In a preferred embodiment of the invention, the surfaces of the carriages also provide upper adjustment surfaces. The accuracy of the linear motion guide is ensured in a preferred embodiment by the highly accurate welds with the aid of gauges. In an equally proposed, alternative embodiment of the invention it is provided that the connection is made - preferably also with a gauge - by gluing. However, the accuracy of the installation is ensured by stop surfaces on the guide rails or the carriage and does not have to be removed by appropriate surfaces on the spacer plates.

Further preferred embodiments of the invention will become apparent from the dependent claims. These preferred embodiments involve further development some of their own inventive developments, but without leading away from the inventive idea.

The aforementioned and the claimed and described in the following embodiments, according to the invention to be used elements are subject to their size, shape, material usage and technical design no special conditions of exception, so that the well-known in the respective field of application selection criteria can apply without restriction.

Further details, features and advantages of the subject matter of the invention will become apparent from the following description of the accompanying drawings, in which - by way of example - a device and an associated process flow to the present invention will be explained.

The invention will be described herein on the basis of a linear motion system in which the spacer plates are first welded, glued or connected in an equivalent manner between the guide rails. It will be clear to one skilled in the art, or it should be understood, that the invention can be extended not only in such a way that the spacer plates are placed both between the guide rails and between the carriages, with any combination of the method of connection included also by arranging such spacer plates only between the carriages.

Furthermore, it will be clear to the person skilled in the art or he is hereby to point out that for the invention in the present description, the process of Einschweissens meant on the one hand very concrete, but on the other hand this Operation representative of other, basically interchangeable operations stands.

Fig. 1

eine Draufsicht auf eine zwei Führungsschienen und zwei Schlitten aufweisendes Linearführungssystem gemäss dem Stand der Technik;

Fig. 2

eine Seitenansicht des zwei Führungsschienen und zwei Schlitten aufweisenden Linearführungssystems gemäss dem Stand der Technik nach Figur 1;

Fig. 3

eine Draufsicht auf ein zwei Führungsschienen und zwei Schlitten aufweisendes Linearführungssystem gemäss einer ersten Ausführungsform der vorliegenden Erfindung;

Fig. 4

eine Seitenansicht des zwei Führungsschienen und zwei Schlitten aufweisenden Linearführungssystem gemäss der Ausführungsform der vorliegenden Erfindung nach Figur 3;

Fig. 5

eine perspektivische Ansicht des zwei Führungsschienen und zwei Schlitten aufweisendes Linearführungssystem gemäss der Ausführungsform der vorliegenden Erfindung nach Figur 3;

Fig. 6

eine Draufsicht auf eine zwei Führungsschienen und zwei Schlitten aufweisendes Linearführungssystem gemäss einer zweiten Ausführungsform der vorliegenden Erfindung;

Fig. 7

eine Seitenansicht des zwei Führungsschienen und zwei Schlitten aufweisenden Linearführungssystems gemäss einer weiteren Ausführungsform der vorliegenden Erfindung.

In the drawing show:

Fig. 1

a plan view of a two guide rails and two carriages having linear guide system according to the prior art;

Fig. 2

a side view of the two guide rails and two slide having linear guide system according to the prior art of Figure 1;

Fig. 3

a plan view of a two guide rails and two carriages having linear guide system according to a first embodiment of the present invention;

Fig. 4

a side view of the two guide rails and two slide having linear guide system according to the embodiment of the present invention according to Figure 3;

Fig. 5

a perspective view of the two guide rails and two slides having linear guide system according to the embodiment of the present invention shown in Figure 3;

Fig. 6

a plan view of a two guide rails and two carriages having linear guide system according to a second embodiment of the present invention;

Fig. 7

a side view of the two guide rails and two slide having linear guide system according to another embodiment of the present invention.

In the linear movement device designated as a whole by 50 in FIG. 4, two guide rails 10 and 12 of the previously known type are provided. Between these guide rails a spacer plate 20 is welded. The welding operation is carried out in the present embodiment so that the welding is carried out by means of a welding jig, are introduced into the two guide rails for defining a predetermined distance. The lower spacer plate 20 is then welded by laser welding. The welding is carried out as line welding in each case over sections of about 20 to 50 mm. Such a weld is made from both sides - top and bottom. It has been shown that a single weld - so only at the top or bottom - does not lead to the required stability. It is particularly advantageous and is therefore also carried out in the embodiment described here, that the lower spacer plate is chamfered before welding at the top. As a result, the weld can be practically sunk into the chamfer of the plate. Likewise, the guide rails are each chamfered on the side facing the lower spacer plate, whereby then the lower weld can also be sunk. In order to further maintain the guide rails with the property of retaining a bottom surface of the linear motion system, the bottom surface of the bottom spacer plate is welded so as to remain above the underside of the guide rails after welding.

Then four carriages 30 and 32 are placed on the guide rails 10 and 12, the carriages 30 and 32 are locked with another gauge and then in a second step an upper spacer plate 60 is laser welded shrink wrapped. This welding is also carried out as a line welding over a section. The line welding is again carried out in each case from both sides of the weld seam between the guide rails and the upper spacer plate. In the present embodiment, the upper spacer plate is chamfered before welding on the side. Also, the outer edges of the carriages are each chamfered on the upper spacer plate facing side. In order to obtain the carriage the property of forming an upper side of the linear motion system, the top of the upper spacer plate is also arranged during welding so that it remains below the tops of the carriage after welding.

In the embodiment described above, the drive is mounted as a linear drive on the two spacer plates 20 and 60. Alternatively, the drive can also be designed in any way already known for such linear drives.

In the linear motion system depicted in FIGS. 3-5, the upper spacer plate is approximately rectangular in shape. Starting from their corners, two welds on the front are made by two carriages and two welds on the back by two more carriages. In this embodiment, the upper spacer plate is thus arranged between the carriages.

In an alternative embodiment according to FIG. 6, the upper spacer plate is approximately rectangular with four rectangular cut-outs at its corners. The carriages are then welded at the positions of the cutouts. This has the property that the welds can be made longer overall, which can lead to a higher strength.

In a further embodiment of the invention, the lower spacer plate is not welded, but glued. Since it is advantageous in existing conditions to find a certain adhesive surface, in this case the guide rails on the inner, lower sides are provided with a cutout or a groove. It will be evident to the person skilled in the art that this embodiment with a groove or a cutout - if necessary also in combination with chamfering according to the above description - can also be used in the first described embodiment with the welded-in spacer plates.

Claims (26)

1. Linear motion guide with at least two guide rails (10, 12) and in each case at least one sled (30, 32) that is supported on each of the guide rails (10, 12) and can be moved along a longitudinal motion axis of the guide, in which the guide rails (10, 12) are envisaged for arrangement on a carrier by way of fastening means,
   characterised in that
   between the at least two guide rails (10, 12) a lower distance plate (20) is welded in, glued in or firmly attached in another manner, whereby in relation to the guide rails (10, 12) the lower distance plate (20) determines the distance between them.
2. Linear motion guide in accordance with claim 1, characterised in that the lower distance plate (20) is welded in and at least one welding seam of the lower distance plate (20) is arranged in a chamfer of the lower distance plate (20).
3. Linear motion guide in accordance with any one of claims 1 or 2, characterised in that at least one welding seam of the lower distance plate (20) is arranged in a chamfer of the guide rails (10, 12).
4. Linear motion guide in accordance with any one of claims 1 to 3, characterised in that the lower side of the lower distance plate (20) remains above the underside of the guide rails (10, 12) after welding in.
5. Linear motion guide in accordance with claim 1, characterised in that the lower distance plate (20) is glued in, whereby the guide rails (10, 12) each have a groove into or to which the lower distance plate (20) is glued.
6. Linear motion guide in accordance with the above claims, characterised in that
   an upper distance place (60) is welded, glued or firmly arranged in another manner between the sleds (30, 32), whereby in relation to the sleds (30, 32) the upper distance plate (60) determines the distances between them.
7. Linear motion guide in accordance with claim 6, characterised in that the upper distance plate (60) is welded in and at least one welding seam of the upper distance plate (60) is arranged in a chamfer of the upper distance plate (60).
8. Linear motion guide in accordance with any one of claims 6 or 7, characterised in that at least one welding seam of the upper distance plate (60) is arranged in a chamfer of the sleds (30, 32).
9. Linear motion guide in accordance with any one of claims 6 to 8, characterised in that the upper side of the upper distance plate (60) remain below the upper sides of the sleds (30, 32) after welding in.
10. Linear motion guide in accordance with any one of claims 6 to 9, characterised in that the upper distance plate (60) is approximately rectangular and in that starting from its corners it is welded onto the front side of two sleds (30) and on the rear side of two further sleds (32).
11. Linear motion guide in accordance with any one of claims 6 to 10, characterised in that the upper distance plate (60) is approximately rectangular with four rectangular cut-outs at its corners and the sleds (30, 32) are welded at the positions of the cut-outs.
12. Linear motion guide in accordance with claim 6, characterised in that the upper distance plate (60) is glued in, whereby the sleds (30, 32) each have a groove or cut-out into or at which the upper distance plate is glued.
13. Method of manufacturing a linear motion guide with at least two guide rails (10, 12) and at least one sled (30, 32) supported on each of the guide rails (10, 12) and movable along a longitudinal motion axis of the guide, in which the guide rails (10, 12) are envisaged for arrangement on a carrier by way of fastening means,
    characterised in that
    between the at least two guide rails (10, 12) a lower distance plate (20) is welded, glued or firmly attached in another manner which in relation to the guide rails (10, 12) determines the distance between them.
14. Method for manufacturing a linear motion guide in accordance with claim 13, characterised in that welding is carried out using a welding template into which the two guide rails (10, 12) are introduced to define a predetermined distance and in that the lower distance plate (20) is welded in by way of laser welding.
15. Method in accordance with claim 14, characterised in that the welding in the first step is carried out over one section at a time as linear welding, whereby the linear welding is carried out from both sides of the welding seam in each case between the guide rails (10, 12) and the lower distance plate (20).
16. Method in accordance with any one of claims 14 or 15, characterised in that the lower distance plate (20) is chamfered on at least the upper side before welding.
17. Method in accordance with any one of claims 14 to 16, characterised in that the guide rails (10, 12) are each chamfered at least on the side facing the lower distance plate (20).
18. Method in accordance with any one of claims 14 to 17, characterised in that the lower side of the lower distance plate (20) is arranged during welding so that after welding it remains above the underside of the guide rails (10, 12).
19. Method in accordance with claim 13, characterised in that the lower distance plate (20) is glued in whereby the guide rails (10, 12) each have a groove or cut-out into or to which the lower distance plates (20) is glued.
20. Method of manufacturing a linear motion guide in accordance with any one of claims 13 to 19, characterised in that in a second step an upper distance plate (60) is welded, glued or firmly attached in another manner between the sleds (30, 32), whereby in relation to the sleds the upper distance plate (60) defines the distance between them.
21. Method in accordance with claim 20, characterised in that said second step welding is carried out with the aid of welding template, into which the at least two guide rails (30, 32) are introduced and in that the upper distance plate (60) is welded in by way of laser welding.
22. Method in accordance with one of claims 21, characterised in that the welding in the second step is carried out over a section as linear welding, whereby the linear welding is carried out from both sides of the welding seam between the sleds and the upper distance plate (60).
23. Method in accordance with any one of claims 21 or 22, characterised in that the upper distance plate (60) is chamfered on at least one side before welding in.
24. Method in accordance with any one of claims 21 to 23, characterised in that the upper side of the upper distance plate (60) is arranged during welding so that after welding it remains above the upper sides of the sleds (30, 32).
25. Method in accordance with any one of claims 21 to 24, characterised in that the upper distance plate is approximately rectangular and that starting from its corners two welding seams are produced on the front side of two sleds (30, 32) and two welding seams on the rear side of two further sleds (30, 32).
26. Method in accordance with any one of claims 21 to 25, characterised in that the upper distance plate (60) is approximately rectangular with four rectangular cut-outs at its corners and the sleds (30, 32) are welded in at the cut-out positions.

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